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Before we start make sure you can ssh into your machine and run
$sudo apt-get update

It’s a four step process:
1. Open the appropriate port on Azure
2. Install pip, virtualenv, virtualenvwrapper, and flask
3. Write our code and run it
4. Keep it running with Gunicorn

1. Open the appropriate ports on Azure
Go to you virtual machines landing:

Then select the resource group in the top left corner:

Resource groups are the way Azure breaks down how our VM interacts with the internet, other vms, storage, and public/private networks.

Top open the port we need to change our network security group, which is represented by the shield. (Underlined in the screenshot above)

Then select settings -> Inbound Security Rules:

This will allos us to open up our VM to the public internet so we can visit what’s presented at the port like a regular website.

You should see SSH already included, that’s the port we’re using in our ssh client/terminal.

We’re now going to add two new Inbound Security Rules one called FlaskPort where we’ll set the destination port range to 5000 and use for debugging. The second will be called FlaskProduction that we’ll use to deploy our complete app.
Here’s the configuration panel for FlaskPort:
Press okay to accept the settings.

And the other panel for FlaskProduction:
Again press okay to accept the settings.

Notice how the ‘Source Port Range’ is ‘*’ that just means that we’ll accept connections from the port of any machine. This tripped me up the first time.

In a couple seconds the port will be open we’ll be ready to visit it, but nothing will be there because we haven’t create an application server.

To do that we’ll install the basics.

2. Install pip, virtualenv, virtualenvwrapper, and flask

To use Python effectively we utilize virtual environments to help keep our various python project and required libraries in order.

If you get lost in these steps or want more context Gerhard Burger provides the same setup on a very helpful post on askubuntu.

First we install pip:$ sudo apt-get install python-pip

Second we install virtualenv and virtualenvwrapper

$ sudo pip install virtualenv
$ sudo pip install virtualenvwrapper

Third we configure virtualenv and virtualenvwrapper

Create a WORKON_HOME string which will contain the directory for our virtual environments. We’ll name it vitualenvs

$ export WORKON_HOME=~/.virtualenvs

Now we’ll create this directory.

$ mkdir $WORKON_HOME

And add this to our bashrc file so this variable is defined automatically every time we hit the terminal.

$ echo "export WORKON_HOME=$WORKON_HOME" >> ~/.bashrc

Then we’ll setup virtualenvwrapper by importing its functions with bashrc.

$ echo "source /usr/local/bin/virtualenvwrapper.sh" >> ~/.bashrc

You can see the additions to our bashrc file by opening it with nano. Scrolling down to the bottom you should see two lines like this:

Then implement your changes.

$ source ~/.bashrc

Here’s what all that looks like all together:

Fourth, let’s create our first virtualenvironment

$ mkvirtualenv venv

And take a look at the currently installed packages$ pip list

Like so:

Now we can install all of the python packages we want without risk of needing to reinstall python!

Fifth, install flask:

$ pip install flask
$ pip list

3. Write our code and run it!
Our first app is a simple site that shares an image.

We’re going to create a folder called Photo-App that contains two folders and an app.py that will serve our clients.

To change to our home directory:$ cd ~
And create our new folder:$ mkdir Photo-App

You’re using gunicorn to start app hosted at 0.0.0.0:8000 with the reload tag configured.
The reload will look for changes in your code and reload the server everytime you change any server side stuff. It won’t auto-reload for HTML changes, but will reload them once you make a change to the python code.